IBM pretty much slammed the solid oak door on open sourcing os/2. "As stated in our response to your September 2005 letter we have considered the positioning of os/2 and open source several times in the past, and for a variety of business, technical, and legal reasons we have decided to not pursue any os/2 open source projects."

You don't need to guess. I worked on this project. IBM is never going to be able to open source OS/2 unless Microsoft agrees. OS/2 contains complete details on SMB/CIFS something that Microsoft does not want public. Probability that Microsoft will agree to open sourcing OS/2 = zero.

There is a big difference between a spec from Microsoft which will be chock full of bugs (maybe on purpose) and a working, tested implementation. Did they get the spec for SMB as well as CIFS, or CIFS only?

There are a bunch of other secret MS technologies in OS/2 too. Remember, this was a joint venture between Microsoft and IBM, not an IBM only project. I worked on OS/2 full time and was a Microsoft employee.